Cold is another word for empty. It isn't really anything. It is, as a vacuum is, the lack
of something. Cold is the lack of heat. The earth we live on is almost empty. We live on
the edge of a delicate temperature balance only some 500° F above empty. The coldest
it can ever get is about -460° F, but "hot-wise" temperatures can reach into
the billions. We live at the bottom of a thermometer that stretches to the moon. Our planet
is a cool puddle in a desert of heat, but water works only at these narrow temperature ranges,
and life depends on this water.

Our planet
must remain empty in order to support life. Refrigerants that leak into the atmosphere cause
damage which allows extra heat to alter and fill our emptiness. Federal and international
regulations have been devised and enacted to curb the release of certain refrigerants into
the atmosphere to prevent our emptiness from being disrupted. A federal licence is required
for handling these refrigerants. If your going to use refrigerants, use them conscientiously.
Much depends on it.

It is the function
of a cooling system to remove unwanted heat from a structure and relocate it to the out
of doors. This heat exchange is accomplished by the use of the refrigeration cycle as performed
by your air-conditioning sytem. The refrigeration cycle takes advantage of the relationships
between pressure, temperature and volume; in such a way that heat is collected inside and
released outside. It uses a condensor, a compressor, and an evaporator to accomplish this
task.

The condensor and compressor are located outside of the house, while the evaporator is
located inside the air distribution system. The quantity of heat that needs to be removed
to maintain indoor comfort, on a specific warm day for your region, is known as the heat
gain for your structure*. A building gains heat from the actual outdoor temperature and
humidity levels. It gains heat from the people inside of it, from the lights, computers,
copiers, dishwashers and ovens. But mostly it gains heat from its exposure to sunlight,
from solar radiation. The hot sun beating down on the walls and the roof, the sunlight pouring
through the windows and warming the floors it lands on.

The sum of all of this heat accumulation is known as the heat gain of the building.

* Many contractors distribute an extra 1500 btu of cooling to
the kitchen to offset the heat given off by the appliances, and an extra 400 btu to various
rooms for occupants.